SUPPLEMENT
SUPPLEMENT
Some new serum chemistry analyses were also added to the protocols. For example, whole blood tau rine levels must be determined on all cats in the tests. Also, serum alkaline phosphatase levels must be run on animals during the maintenance trials. The latter test is intended to assure adequate calcium in the diet, whereas the previous maintenance trial would not be able to detect an adverse effect. The subcommittee recognized that this parameter was not ideal in terms of specificity or sensitivity, but weighed potential benefit against the cost and impracticality of other means (e.g., parathormone assays, bone densitometry). Unequivocal proof of a product's nutritional ade quacy for all animals under all conditions can never be achieved. However, with the changes in both the nutrient profiles and feeding trial protocols, assurances of nutritional adequacy to the consumer have been improved. Substantiation of the nutritional adequacy of a pet food based on the nutrient profiles may be less reliable than the results of feeding trials. For ex ample, the nutrient profiles cannot assess the accept ability, palatability and other factors of a product as well as the feeding trials. Also, although formulations should be adjusted to account for nutrient levels at the time of feeding, processing losses can remain a factor. On the other hand, the validity of a feeding trial greatly depends on the competence and integrity of the conductor of the trial. Especially in the mainte nance trials, subtle chronic nutrient deficiencies or ex cesses can be overlooked. In the future, this author envisions a hybridization of the two methods.